Question

In basic medium CrO^2-₄ oxidises  S₂O^2-₃ to form SO₄^2– and itself changes into Cr(OH)^-₄ . The volume of 0.154 M CrO^2-₄ required to react with 40 mL of 0.25 M S₂O^2-₃ is ....... mL.

Answer 1

gm equi. of CrO₄^2– = S₂O₃^2–

0.154 × 3 × v = 0.25 × 40 × 8 

v = 173.16 = 173 ml